Injection nozzle for internal combustion engines



0. BAUR June 7, 1932.

INJECTION NOZZLE FOR INTERNAL COMBUSTION ENGINES Filed June 11. 1929 9M0m Kiw/ Patented June 7, 1932 UNITED STATES PATENT! OFFICE 1 OTTIM'ARBAUR, OF STUTTGART, GERMANY, A SSIGNOB TO ROBERT BOSCH AKTIEN-GESELLSCHAFT, OF STUTTGART, GERMANY INJECTION NOZZLE FOR INTERNALCOMBUSTION ENGINES Application filed June 11, 1929, Serial no. 369,984,and in Germany August so, 1928.

This invention relates to a fluid-controlled holder transmits itsclosing pressure to the In the needle through a connecting rod.

known jets of this type the limiting of the m movement of the jet needleis effected by a stop engaging the connecting rod so that in addition totransmitting the tension of the closing spring, the said connecting rodalso transmits the very considerable force acting on the surface of theabutment limiting the movement. This may result in deformation of theconnecting rod, which is kept as light and thin as possible and isusually very long, and this deformation will cause a variation in thelength of the needle stroke.

According to the invention this disadvantage is removed by the abutmentlimiting the movement engaging directly on one shoulder of the raisedneedle so that the connecting rod only has to transmit the tension ofthe closing spring. If the raised needle guided in the jet member isallowed to abut with one shoulder against a flange of the jet holder,the limitation of movement thus obtained will be considerably simplerthan in the known ets.

One form of construction of the object of the invention is shown inlongitudinal section in the drawing.

known manner the fluid controlled jet needle d presses against the lowerend of the jet holder (1 by means of a screw cap b. The needle carriesat its other end a pin f of less diameter than spindle e mounted in thejet member and projecting into the holder a. One end of a connecting rod9 engages the pin whilst the other end bears against the closing springh mounted inthe upper portion of the holder, a spring washer beinginterposed. p

The lower face of the jet holder, against which the jet member isforced, partially covers a needle guide aperture in the et memeo ber.This covering portion 2' forms an abut- A jet member 0 in which isinserted in of greater diameter than said aperture, said ment for theshoulder 11 of the pin f on the guide spindle e of the jet needle. Theplay- 122. between the abutment z and the. shoulder determines themaximum movement of the needle which is not adjustable in the exampleshown;

I claim:

1. An injection nozzle for internal combustion' engines comprising incombination a holder, a jet membermounted on said holder. and having abore formed therein, a piston element mounted in said bore, a needlecarried by one end of said piston element, said piston element being ofa length less than the bore by the predetermined amount of lift of theneedle, a pin of less diameter than the piston element mounted upon theother end of said piston element and extending into an aperture formedin said holder of less diameter than the bore, whereby said pistonelement abuts against said holder to limit the opening of said needle. V

2. An injection nozzle for internaI combustionengines comprising incombination a holder, a jet member having a bore formed 75 therein, apiston member of less length than said boremounted therein, a needlecarried by one end of said piston memberand coop- 'erating with a nozzleopening in said jet member, said jet member being mounted upon saidholder to partially close the open end of said bore and limit themovement of said piston, a pin of less diameter than the piston mountedupon the other end of the piston and extending into an aperture 35formed in said holder of less diameter than said bore, and a loadingspring mounted in said holder and cooperating with said pin to bias saidneedle to the closed position.

3. An injection nozzle for internal combustion engines comprising incombination a holder having a plane surface area within which is locatedan aperture of a fuel duct,

a jet member having a bore formed therein jet member being mounted onsaid plane surface with said bore in registry with said aperture, apiston element mounted in said bore, a needle carried by one end of saidpiston element, said piston element being of a len h less than the boreby the predetermine amount of lift of the needle, a pin of less diameterthan the piston element mounted upon the other end of said pistonelement and extending into said aperture, and a loading spring mountedin said holder and cooperating with said pin to bias said needle toclosed position.

4. An injection nozzle for internal combustion engines comprising incombination a holder having a plane surface area within which is locatedthe aperture of a fuel supply duct and the aperture of a fuel drainageduct, a jet member having a bore formed u therein of a greater diameterthanthe aperture of said drainage duct and being provided also with afuel duct adapted to register with the fuel supply duct on said holder,said jet member being mounted on said plane so surface with said bore inregistry with said drainage aperture and with registry between said fuelsup ly ducts, a piston element mounted in said bore, a needle carried byone end of said piston element, said piston eleu ment being of a lengthless than the bore by the predetermined amount of lift of the needle, apin of less diameter than the piston element mounted upon the other endof said piston element and extending into said aperao ture, and aloading spring mounted in said holder and cooperating with said pin tobias said needle to closed position.

In testimony whereof I have hereunto afiixed my signature. OTTMAR BAUR.

